Why don't you read this: http://www.mylot.com/o/faq/faq10.aspx ? This FAQs may answer your question about photos uploaded in mylot. Currently, you can't upload photos in discussions in order to get earning. You may upload photos for your avatar only.
When you are allowed to upload photos or images, you can uploaded any images. You can upload your own photos or photos belong to others as long as the photos are not protected by the law (copyright). As long as your photos meet the requirement as said in FAQs, you may uploaded them.

If you read carefully in the link that you provided you will see that it says:
"Only users with a rating over 500 will be allowed to upload photos into comments and responses".
All users can upload photos when they start a discussion and to their interests.

As a new user, it would be fine if you'll find time to read the myLot guidelines. The answer to your question can be found there.
Look into the photo guidelines here: http://www.mylot.com/o/photoguidelines.aspx
You should also read the FAQs. There's a lot of tips about what you should do here.
Good luck!